JPH08182110A - Generator controller for hybrid electric vehicle - Google Patents

Abstract

PURPOSE: To prevent the battery voltage or the motor output from lowering by compensating for the power being discharged from a battery during an immediately preceding period at a specified control period based on variables for managing the balance of charge/discharge, thereby balancing the charge/discharge of the battery. CONSTITUTION: A control target of generator output, being set based on the smoothed value of output from a motor 10 during an immediately preceding control period, is compared with a maximum output from a generator 24. When the control target is higher, it is lowered below the maximum generator output and a value corresponding to the discharged output of a battery 16 is accumulated to a variable for managing the balance of charge/discharge. Power discharged from the battery 16 during an immediately preceding control period is then compensated based on the variable for managing the balance of charge/discharge at a control period which caused to set a control target lower than the maximum generator output based on the smoothed value of output from the motor 10. With such arrangement, charge/discharge of the battery 16 can be balanced well in the early stage even if the rating of the generator 24 or the battery 16 is insufficient for the required acceleration performance thus preventing the battery 16 voltage or the motor 10 output from lowering.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid electric vehicle having an engine and a motor mounted together, and more particularly to a generator control device for controlling a generator driven by the engine to supply electric power to a motor and a battery.

[0002]

2. Description of the Related Art In a system configuration called a series hybrid vehicle (SHV) among hybrid electric vehicles, drive power is supplied from a vehicle-mounted battery as well as a vehicle-mounted engine-driven generator to a vehicle drive motor. The engine-driven generator is composed of an engine and a generator driven by this engine, and the power output of the generator can be supplied to both the battery and the motor. In addition, WOT (wide open throttle)
By operating at 1, the engine speed can be controlled only by the field current of the generator, which is the load, and therefore the power generation output of the generator can be controlled by the field current. Further, the WOT operation can improve fuel efficiency and emission.

[0003]

In particular, in the technique proposed by the applicant of the present application in Japanese Patent Application No. 5-237547, the motor output is first detected and smoothed in a certain control cycle. Further, the power generation output of the generator in the next control cycle is controlled based on the control target value set according to the obtained smoothed value (average value or the like). By performing such control, the charge and discharge balance of the battery can be almost balanced, and therefore the state of charge (SO
Since C) can be maintained within a predetermined range, it is possible to extend the life of the battery and suppress the frequency of charging by the external power source. Also, instead of using the detected value of the motor output as it is as the control target of the generated output of the generator, it is used as the control target of the generated output of the generator after processing such as smoothing the detected value of the motor output. As a result, it is possible to suppress fluctuations in the engine speed, improve engine emissions, and achieve a drive feeling similar to that of a gasoline engine vehicle.

However, with such a method alone,
Problems may occur due to the rated settings of motors and generators. In other words, since only the maximum power generation output equivalent value of the generator can be set as the power generation output control target at most, under the situation where the smoothed value of the motor output detection value exceeds the maximum power generation output of the power generator, The amount corresponding to the difference between the target values must be borne by the discharge from the battery, resulting in an imbalance of the charge and discharge balance of the battery to the discharge side. This impedes advantages such as a longer life of the battery and suppression of the frequency of charging by an external power source, and, in a conspicuous case, causes a decrease in battery voltage and a decrease in motor output due to over discharge of the battery.

In order to overcome this problem, the maximum power generation output of the generator may be set to be large, or at least about the same, as the maximum output of the motor. However, such a setting is not rational in terms of downsizing of the generator and the battery. In other words, the frequency of situations in which the motor must be driven with a large amount of power is not so high in daily use, so the generator's rating should be set so as to satisfy the cruise performance required for the vehicle. In addition to downsizing the machine, it is also rational in downsizing the battery that receives the power output. On the other hand, in order to meet the demand for high acceleration, it is necessary to design the motor so that it can be driven with high power. In this way, the generator rating required according to the cruise performance is usually set to a value that is about 1/3 smaller than the motor rating set according to the required acceleration performance. If such a rating is set, it is difficult to avoid the above-mentioned imbalance of charge / discharge balance of the battery.

Further, the engine has a region where WOT operation cannot be performed. That is, when the required output to the motor is small, the required output cannot be covered by the engine-driven generator alone unless the throttle of the engine is closed, and when the throttle is closed, the fuel economy deteriorates because the engine goes out of the WOT line.

The present invention has been made to solve the above problems, and when the smoothed value of the motor output exceeds the maximum power output of the engine-driven generator, the discharge output of the battery is changed. By paying attention to the control, the unbalance of the charge and discharge balance of the battery can be further reduced while keeping the generator and the battery small in size, thus achieving the long life of the battery and the suppression of the charging frequency by the external power supply. ,
In addition, a first object is to prevent a decrease in battery voltage and a decrease in motor output due to over-discharge of the battery. INDUSTRIAL APPLICABILITY The present invention reduces noise by driving power generation control immediately after transitioning from high-load running with a large motor output to medium-low load running with a small motor output, thereby reducing discomfort in the drive feeling and reducing battery voltage. The second purpose is to prevent the generation of loss and the activation of the voltage protection function due to the rise of the voltage. The present invention prevents the discomfort caused by a large increase in the power generation output when the motor output is greatly decreasing by controlling the power generation output during the transition from high load running to medium / low load running. The purpose is 3. The present invention prevents the engine from operating at low efficiency by controlling the power generation output of the engine-driven generator when the smoothed value of the motor output falls below the minimum power generation output capable of operating the engine with high efficiency, and deteriorates fuel efficiency. A fourth object is to prevent the above problems and to balance the charge and discharge balance of the battery.

[0008]

In order to achieve such an object, the generator control device of the present invention uses a power generation output in the current control cycle based on the smoothed value of the index value of the motor output in the immediately previous control cycle. Means for setting the control target of
A means for determining whether the set control target exceeds or falls below the maximum power generation output that can be supplied from the generator, and when it is determined to exceed the above, the control target is reduced and corrected so as to be below the maximum power output, A means for adding a value obtained by subtracting the control target after reduction correction from the control target before reduction correction to the variable for charge / discharge balance management, and when it is determined to be less than the value obtained by subtracting the above control target from the maximum power generation output. And a means for adding the reduced amount to the control target, and a means for controlling the power generation output of the generator according to the control target.

The generator control device of the present invention is such that when the control target is below the maximum power generation output, and the control target exceeds the allowable output, the power output has a value less than or equal to the maximum power generation output. Is provided with a means for limiting the amount of addition to the control target so as not to exceed the control target.

The generator control device of the present invention limits the amount of addition to the control target so that the control target does not increase by a predetermined allowable increase amount or more when the control target is below the maximum power generation output. It is characterized by including.

The generator control device according to the present invention comprises means for determining whether the set control target exceeds or falls below the minimum power generation output capable of operating the engine with high efficiency, and when it is determined that the control target falls below the minimum power output. Is forcibly set to 0 or a value equal to or greater than the minimum power generation output, and a value obtained by subtracting the control target before the compulsory setting from the control target after the compulsory setting is added to the charge / discharge balance management variable, and it is determined that it exceeds the value. In this case, there is provided means for reducing the charge / discharge balance management variable by an amount equal to or less than a value obtained by subtracting the control target from the maximum power generation output, and adding the reduced amount to the control target.

The generator control device of the present invention comprises means for detecting that the motor output is substantially below the minimum power output based on the above index value, and idling the engine when it is detected to be below. Or, a means for stopping, a means for detecting that the motor output substantially exceeds the minimum power generation output based on the index value, and a control output in the case where it is detected that the motor output exceeds the minimum power generation output And a means for forcibly setting.

[0013]

In the present invention, first, the control target of the power generation output in the current control cycle is set based on the index value smoothed value of the motor output in the immediately previous control cycle. The set control target is compared with the maximum power generation output that can be supplied from the generator. As a result, when it is determined that the value exceeds the control target, the control target is reduced and corrected so as to be equal to or less than the maximum power generation output. A value obtained by subtracting the control target after the reduction correction from the control target before the reduction correction is added to the charge / discharge balance management variable. When the control of the power generation output is executed according to the corrected control target,
The charge and discharge balance of the battery temporarily tilts toward the discharge side. This imbalance is compensated for in later control cycles. That is, when it is determined that the control target set based on the smoothed value of the index value of the motor output is less than the maximum power generation output, the value of the charge / discharge balance management variable is reduced and the control target is increased and corrected by the reduction amount. It When the power generation control is performed based on this control target, the battery discharge that has occurred in the previous control cycle is compensated, and as a result, the charge / discharge balance of the battery is corrected to a balance closer to the balanced state from the discharge side up to now. As described above, in the present invention, since the imbalance of the charge and discharge balance of the battery is reduced, the effects of extending the life of the battery, suppressing the frequency of charging by an external power source, and preventing over-discharge of the battery occur. Further, the size of the generator or the battery is not increased.

In the present invention, the increase correction amount of the control target of the power generation output is limited in the control cycle in which the compensation of the battery discharge should be performed.

First, by limiting the increase correction amount, the control target is prevented from exceeding the allowable output. This allowable output is set to a value less than or equal to the maximum power generation output. In this case, in the control cycle in which the motor output is lower than that in the immediately preceding control cycle, such as immediately after the transition from high-load running to medium-low load running, the power generation target and eventually the power generation output increases. The noise is prevented from being exposed. This leads to reduction of discomfort in drive feeling. Further, when the battery voltage rises as the power generation output increases, a loss occurs due to a decrease in the charging efficiency of the battery, but the present invention also prevents such a loss. Further, in the case of adopting a system configuration in which power generation is stopped when the battery voltage rises, from the viewpoint of overcharging the battery, preventing gas generation in the battery, and the like, it is possible to prevent such activation of the protection function.

Secondly, the increase correction amount is limited so that the increase amount of the control target does not exceed the allowable increase amount. In this case, even when the motor output is significantly reduced compared to the immediately preceding control cycle, such as when transitioning from high load running to medium / low load running, the power generation target, and thus the power generation output, is reduced. There is no sense of discomfort because there is no sudden increase.

In the present invention, it is also determined whether the control target set based on the smoothed index value of the motor output exceeds or falls below the minimum power generation output capable of operating the engine with high efficiency. When it is determined that the value falls below the control target, the control target is forcedly set to 0 or a value equal to or greater than the minimum power generation output. At the same time, the difference between the control target before the forced setting and the control target after the forced setting, that is, the newly generated imbalance of the charge / discharge balance is added to the charge / discharge balance management variable. Therefore, the engine is controlled to be in either a highly efficient operating state or a stopped (or idling) state, so that the engine is not driven with low efficiency and deterioration of fuel consumption is prevented. In addition, when it is determined that the value exceeds the value of the charge / discharge balance management variable, the control target is corrected by the reduced amount. As a result, even if the charge / discharge balance of the battery is temporarily inclined toward the discharge side or the charge side due to the difference between the motor output and the power generation output due to the correction of the power generation target when the motor output decreases, this imbalance Is resolved early.

In the present invention, alternatively, the motor output is compared with the minimum power generation output, and the engine is idling or stopped when the former can be regarded as substantially lower than the latter. After that, when the motor output substantially exceeds the minimum power generation output, power generation control is executed with a target value of the minimum power generation output or higher. Therefore, in the present invention, the engine is controlled to either the highly efficient operating state or the stopped or idling state, so that the engine is not driven with low efficiency and deterioration of fuel efficiency is prevented. . Further, since the engine is idling or stopped based on the index value of the motor output instead of the smoothed value of the index value of the motor output, the period during which the motor output decreases and the period during which the engine idles or stops coincides with each other. It is possible to prevent the engine noise from being exposed and the drive feeling from being deteriorated.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an S suitable for implementing the present invention.
The system configuration of the HV is shown. In this system, a three-phase AC motor is used as a motor 10 for running a vehicle, and the output shaft of the motor 10 is driven by a differential gear (differential gear) 12 and other mechanisms.
Connected to four.

A battery 16 and an engine-driven generator 18 are mounted as a drive power source for the motor 10.
The discharge output of the battery 16 and the power generation output of the engine-driven generator 18 are both DC power, which is converted into three-phase AC by the inverter 20 and then supplied to the motor 10.
The power output of the engine-driven generator 18 is also used to charge the battery 16. Further, when the vehicle is regeneratively braked, the battery 16 is charged by the electric power regenerated by the motor 10.

The engine-driven generator 18 is composed of an engine 22 which is exclusively operated by WOT and a generator 24 which is driven by the engine 22. That is, the output of the engine 22 is increased by the speed increaser 26 to a speed suitable for the generator 24, and then supplied to the generator 24. When the field current If is supplied to the generator 24 in this state, a power generation output is obtained from the generator 24. In this figure, a three-phase AC generator is used as the generator 24, and the generated output is rectified by the rectifier 28 in the subsequent stage and then supplied to the inverter 20 and the battery 16.

Output of motor 10 and engine driven generator 1
The power generation output of 8 and the SOC of the battery 16 are controlled or managed by the controller 30. The controller 30 includes a motor controller 32 that controls the motor 10, and a generator controller 34 that controls the engine-driven generator 18. The motor controller 32 and the generator controller 34 are
Information is exchanged as appropriate during the operation. further,
The SOC of the battery 16 is managed by the motor controller 3
2 and the generator controller 34 cooperate with each other, that is, as the control of the power generation output according to the motor output.

The motor controller 32 inputs an accelerator amount, a brake amount and the like indicating an acceleration / deceleration request from the vehicle operator, while detecting a motor rotation speed N using a rotation sensor 36 attached to the motor 10. Motor controller 3
2 determines the output torque to be generated by the motor 10, that is, the torque command, based on these pieces of information. The motor controller 32 uses the determined torque command to detect the motor current I detected by the current sensor 38.
While referring to M, the power conversion operation by the inverter 20 is controlled. Here, the inverter 20 is composed of a predetermined number of switching elements, and has a function of converting a DC voltage into a three-phase AC current by the switching operation of these elements. Therefore, the motor controller 3
Switching control signal SW from 2 to the inverter 20
By supplying the motor current IM so that the motor 10 has a current necessary to realize the torque command.
Can be controlled. As will be apparent from the following description, the present invention should not be limited by the details of the operation of the motor controller 32, for example, the presence or absence of the rotation sensor 36 or the current sensor 38, and the operation algorithm of the motor controller 32.

In the system of this figure, the engine 2
2 is used with high efficiency, that is, in the region where fuel consumption is good and emissions are low. In particular,
By operating the engine 22 generally at WOT, deterioration of fuel consumption due to throttle operation is prevented. Also,
When the engine 22 is in the WOT operation, the power generation output of the engine-driven generator 18 can be controlled by the field current If of the generator 24. In the system of this figure, the generator controller 34 controls the power generation output of the engine-driven generator 18 by the field current If. At that time, the generator controller 34 feeds back the power generation output of the engine-driven generator 18 to the control target Pg, so that the engine 22
Input the rotation speed from.

The generator controller 34 controls the control target Pg.
In addition to the above feedback, the output power of the motor 10 or the input power to the inverter 20 (hereinafter, these are collectively referred to as "motor power consumption Pm". Loads other than the motor 10 (not shown) (Including consumption by))). The motor power consumption Pm is obtained by multiplying the torque command and the motor rotation speed N, or the input current Ii to the inverter 20 and the battery voltage V.
It can be obtained by multiplying by b. The generator controller 34 smoothes (averages) the motor power consumption Pm thus obtained over a control cycle having a predetermined length T, and controls the average power consumption Pave obtained as a result in the next control cycle. Used as the target Pg. The generator controller 34 controls the field current If while referring to the engine speed so that the determined control target Pg is realized as a power generation output of the engine drive generator 18. In the present invention, instead of the motor power consumption Pm,
It can also be implemented using other indicators that reflect this. For example, the motor rotation speed (vehicle speed) N, the torque command, or the estimated value may be used. If the vehicle speed or the motor rotation speed N is used, the feeling is further improved.

In order to realize such control, in FIG. 1, a current sensor 40 for detecting the output current Ig of the rectifier 28, a current sensor 42 for detecting the charging / discharging current Ib of the battery 16, and an input current to the inverter 20. A current sensor 44 that detects Ii and a voltage sensor 46 that detects the terminal voltage Vb of the battery 16 (and thus the terminal voltage of the rectifier 28 and the inverter 20) are used. Current sensor 44
Since the product IiVb of the output of the voltage sensor 46 and the output of the voltage sensor 46 represents the motor power consumption Pm as described above, it can be used as a basis for determining the average power consumption Pave. Also, the product of the output of the current sensor 40 and the output of the voltage sensor 46 IgVb
Represents the power output of the engine-driven generator 18, and can be used as a feedback amount in the target control. However, these sensors are not essential for implementing the present invention.

By the way, the average power consumption Pave may exceed the maximum power generation output PgMax of the engine-driven generator 18 and may fall below the minimum power generation output PgMin. The maximum power generation output PgMax refers to the maximum power generation output that can be output from the engine-driven generator 18 with high efficiency on the basis of the rating of the power generator 24 and the like, and the minimum power generation output PgMin is high efficiency from the engine-driven generator 18. The minimum power generation output that can be output (for example, about 1/5 of PgMax). In the above-described system, since the efficiency of the engine 22 is maintained by the WOT operation, the relationship between the power generation output and the engine speed and the relationship between the maximum power generation output PgMax and the minimum power generation output PgMin and the engine speed are shown in FIG. The relationship is as follows.

Therefore, if the control target Pg is simply determined according to the average power consumption Pave, the power generation output will be insufficient and the operating efficiency of the engine 22 will be reduced. For example,
In a high load traveling state in which the motor power consumption Pm is remarkably large, the average power consumption Pave becomes large, so the control target Pg may exceed the maximum power generation output PgMax. In this case, the power generation output actually obtained from the engine-driven generator 18 is limited to the maximum power generation output PgMax, so that the electric power corresponding to the difference between the control target Pg and the maximum power generation output PgMax is covered by the discharge of the battery 16. This problem,
It becomes apparent when the rating of the generator 24 is set smaller than the rating of the motor 10. On the contrary, the average power consumption Pave in the low load traveling state in which the motor power consumption Pm is remarkably small.
Becomes smaller, the control target Pg becomes the minimum power generation output PgMi.
It may fall below n. In this case, the throttle of the engine 22 must be closed in order to obtain the power generation output equivalent to the control target Pg from the engine-driven generator 18.
The operation efficiency of the engine 22 is deteriorated, and thus the fuel consumption is deteriorated.

In each of the following embodiments, if the control target Pg is simply determined according to the average power consumption Pave, the control target Pg will be set in a situation where the power generation output is insufficient and the operating efficiency of the engine 22 is reduced. These problems are prevented or alleviated by performing a predetermined operation.

First embodiment. FIG. 3 shows a control procedure executed by the generator controller 34 in the first embodiment of the present invention. As shown in this figure, the generator controller 34 first clears the built-in timer and sample data to 0 (100), and then sets the motor power consumption Pm during one control cycle having a predetermined length T seconds. Sampling (104). When the count value of the built-in timer reaches T seconds, the generator controller 34 (10
2), motor power consumption Pm sampled so far
The average of is calculated (106). In this way, the average power consumption P that is the basis for determining the control target Pg of the generated output
ave is obtained.

The generator controller 34 subsequently compares the average power consumption Pave with the maximum power generation output PgMax and the minimum power generation output PgMin (108). As a result, when it is detected that the average power consumption Pave exceeds the maximum power generation output PgMax, the generator controller 34 adds the difference Pave-PgMax between the two to the variable Pd for managing the charge / discharge balance of the battery 16 ( 110), the power generation output of the engine-driven generator 18 is controlled with the maximum power generation output PgMax as the control target Pg (112). That is,
When the average power consumption Pave exceeds the maximum power generation output PgMax, even if the average power consumption Pave is set as the control target Pg as it is, the engine-driven generator 18 cannot realize this, and in this case, the maximum power generation output PgM.
The field current If is controlled by setting ax to the control target Pg. When the engine-driven generator 18 is controlled with the maximum power generation output PgMax as the control target Pg, Pave-P
Since the electric power corresponding to gMax is carried by the discharge of the battery 16 and its charge / discharge balance is inclined to the discharge side, Pave-PgMax is set to the management variable Pd in order to quantitatively handle how much the discharge side is inclined. Add up.

Average power consumption Pa in step 108
When it is detected that ve is less than the minimum power generation output PgMin, the generator controller 34 integrates the average power consumption Pave with the management variable Pd (114), and the control target Pg.
Is set to 0 to control the engine-driven generator 18 (11
6). That is, when the average power consumption Pave is below the minimum power generation output PgMin, this average power consumption Pa
If the engine drive generator 18 is controlled with ve as it is as the control target Pg, the throttle of the engine 22 must be controlled to the closing side, resulting in a reduction in efficiency. In this case, the engine 22 is idling or stopped and the field current is reduced. By controlling If to 0, the power generation output of the engine-driven generator 18 is controlled to 0. As a result, it is possible to avoid deterioration of fuel efficiency due to low efficiency driving. Further, when the power generation output of the engine-driven generator 18 is controlled to 0, Pa
Since the electric power corresponding to ve is carried by the discharge of the battery 16 and the charge / discharge balance thereof is inclined toward the discharge side, the average power consumption Pave is integrated with the management variable Pd.

Average power consumption Pa in step 108
ve is the minimum power generation output PgMin or more and the maximum power generation output PgM
When it is detected that it is equal to or less than ax, the generator controller 34 sets the control target Pg by using the amount accumulated in the management variable Pd in the previous process, and the generator controller 34 sets the control target Pg in the previous process. The charge / discharge balance is compensated for the amount of inclination to the discharge side. Specifically, the addition value Pref of the average power consumption Pave and the value of the management variable Pd is calculated (11
8) The engine-driven generator 18 is controlled with this as the control target Pg of the power generation output (120). As a result, the battery 16 is charged with the amount of electric power corresponding to the electric power accumulated by the management variable Pd. Therefore, the integrated value of the power generation output shortage that has occurred in the previous process, that is, the portion of the motor power consumption Pm that was covered by the discharge of the battery 16 is compensated, and the charge / discharge balance of the battery 16 is charged / discharged. Returns to a balanced state. Further, in order to reflect that the charge and discharge are balanced, the management variable Pd is also reset to 0 when step 120 is executed (12
2).

However, only the processing of steps 118 to 122 cannot deal with the case where the added value Pref exceeds the maximum power generation output PgMax. That is, when the added value Pref exceeds the maximum power generation output PgMax, the engine driven generator 18 sets the added value Pref as the control target Pg.
Even if is controlled, this control target Pg cannot be realized. Therefore, in this embodiment, steps 122 and 12 are performed.
Prior to 0, the added value Pref is compared with the maximum power generation output PgMax (124). As a result, if the added value Pref is less than or equal to the maximum power generation output PgMax, the above step 1 is performed.
22 and 120 are executed. On the contrary, if the added value Pref exceeds the maximum power generation output PgMax, the control target P
Step 11 to limit g to the maximum power generation output PgMax
2 is executed. At this time, step 110 is also executed, and the electric power PgMax-Pave corresponding to the amount of electric power charged in the battery 16 by the current power generation is the management variable Pd.
Reduced from.

FIG. 4 shows the above-mentioned control procedure as a timing chart. Here, the control periods A, B, ... Each having a predetermined length of T seconds are assumed, and a situation is considered in which the motor power consumption Pm gradually decreases with a temporary fluctuation. In this situation, the average power consumption Pave gradually decreases as the motor power consumption Pm decreases. Therefore, at the beginning, the maximum power generation output PgMa
The average power consumption Pave, which has exceeded x, also becomes less than or equal to the maximum power generation output PgMax in a certain control cycle. In the present embodiment, the shortage of the power generation output is compensated in the control cycle after the control cycle in which the average power consumption Pave in the immediately previous control cycle starts to become the maximum power generation output PgMax or less.

For example, since the average power consumption Pave in the control cycle A exceeds the maximum power generation output PgMax as shown in the column of the control cycle B, in the control cycle B, the maximum power generation output PgMax is set as the control target Pg. Control is performed. At this time, the shortage Pave-PgMax is added to the management variable Pd (). Since the average power consumption Pave in the control cycle B also exceeds the maximum power generation output PgMax, the same processing is executed in the control cycle C as well. The average power consumption Pave in the control cycle C is less than or equal to the maximum power generation output PgMax as shown in the column of the control cycle D, but since Pref> PgMax, in the control cycle D, PgMax is set as the control target Pg of the power generation output. Control is performed, and the management variables Pd to PgMax-
Pave is reduced (). The average power consumption Pave in the control cycle D is equal to or less than the maximum power generation output PgMax as shown in the column of the control cycle E, and Pref
Since ≦ PgMax, the power generation output is controlled with Pref as the control target Pg in the control cycle E, and the management variable Pd is reset to 0 ().

Thus, according to this embodiment, the generator 2
Since the rating of No. 4 is set smaller than that of the motor 10, the charge / discharge balance of the battery 16 can be prevented from deteriorating although the average power consumption Pave may exceed the maximum power generation output PgMax. Further, since the throttle of the engine 22 is not closed even when the average power consumption Pave falls below the minimum power generation output PgMin, it is possible to prevent deterioration of fuel efficiency of the engine 22 due to low efficiency operation. Further, the deviation of the charge / discharge balance that occurs when the average power consumption Pave is not in the WOT operation region, that is, the region between the minimum power generation output PgMin and the maximum power generation output PgMax, means that the average power consumption Pave subsequently enters the WOT operation region. It can be solved appropriately in a controlled cycle.

Second Embodiment. FIG. 5 shows a control procedure executed by the generator controller 34 in the second embodiment of the present invention. However, in this figure, only the parts different from those in FIG. 3 are shown. In this example,
After execution of step 106, the average power consumption Pave is compared with the minimum power generation output PgMin, the power generation target limit value PhMax, and the maximum power generation output PgMax in step 124.
However, the power generation target limit value PhMax is at least PgM.
For example, a value of about 60% of the maximum power generation output PgMax is set so that in <PhMax <PgMax. As a result of this comparison, the average power consumption Pave is the maximum power generation output Pg.
The operation when it is detected that it exceeds Max or when it is detected that it falls below the minimum power generation output PgMin is the same as that of the first embodiment.

In step 124, PhMax ≦ Pa
If ve ≦ PgMax is detected, the first
If the same control as in the embodiment is performed, the maximum is PgMax-Pav.
Although the charge / discharge balance of the battery 16 can be improved by the amount corresponding to e, the average power consumption Pav in this embodiment is
The engine drive generator 18 is controlled with e being the control target Pg (126). The reason for performing such control is to prevent noise increase, loss occurrence, activation of the voltage protection function, and the like. That is, the process of the first embodiment for eliminating or reducing the imbalance of the charge / discharge balance generated in the previous control cycle in the subsequent control cycle is performed by the motor as in the example of FIG. 4 described above. It is often executed in a situation where the power consumption Pm is gradually changing from a large value to a small value.
In other words, even though the output of the motor 10 has already decreased, the power generation output increases, so that the noise generated in the generator 24 is often noticeable. this is,
It causes a feeling of strangeness in the drive feeling. Further, when the battery 16 is charged with a large amount of electric power, the battery voltage Vb rises, and eventually the charging efficiency drops. Further, in order to prevent overcharge and gas generation in the battery 16, in a system having a voltage protection function of reducing the power generation output to 0 to a minute value when the battery voltage Vb rises, a command to generate power with large power is issued. This may cause the suspension of power generation. In this embodiment, in order to realize a system having a better drive feeling, a smaller loss, and not in conflict with the voltage protection function, PhMax ≦ Pav.
The power generation output is limited to Pave when e ≦ PgMax is satisfied.

In step 124, PgMin ≦ Pa
When it is detected that ve <PhMax, the generator controller 34 executes step 116 and then step 128 in which PgMax in step 124 is replaced with the power generation target limit value PhMax.
When it is determined in step 128 that Pref ≦ PhMax, the generator controller 34 proceeds to steps 122 and 1
Run 20. In step 128, Pref> PhM
When it is determined to be ax, the generator controller 34 replaces PgMax in steps 110 and 112 with the power generation target limit value PhMax, steps 130 and 13.
Execute 2. These replacements are in line with the introduction of the power output limitation by steps 124 and 126 in this embodiment.

As described above, according to this embodiment, the same advantages as those of the first embodiment can be enjoyed, and the increase of noise, the occurrence of loss, the activation of the voltage protection function, etc. can be prevented.

Third Embodiment. FIG. 6 shows a control procedure executed by the generator controller 34 in the third embodiment of the present invention. In this figure, parts common to those in FIG. 3 or 5 are omitted.

In this embodiment, when it is detected in step 124 that PgMin≤Pave <PhMax, the value of the management variable Pd is compared with a predetermined power generation target increase amount limit value Ptr (134). As a result, P
When it is detected that d <Ptr, the generator controller 34 performs steps 118 to 1 in the second embodiment.
22 and step 118 with contents similar to 128-132
Perform A-122A and 128A-132A. Pd
If ≧ Ptr is detected, the generator controller 34 proceeds to steps 118-122 and 128-13.
Steps 118B to 122B and 12 having the same contents as 2
8B to 132B are executed. However, in step 122B, the power generation target increase amount limit value Ptr is subtracted from the management variable Pd instead of resetting the management variable Pd to zero.

Therefore, in this embodiment, when the charge / discharge balance imbalance that has occurred in the previous control cycle is eliminated or reduced based on the information accumulated in the management variable Pd, the increase amount of the control target Pg is increased. Power generation target increase limit value Pt
Limited to r. Therefore, the power generation target increase amount limit value Ptr
By appropriately setting the value of, it is possible to prevent the difference between the power generation output and the motor output from widening, and it is possible to reduce the discomfort in the drive feeling. In this embodiment, the same effect as the first and second embodiments can be obtained.

Fourth Embodiment. The present invention is not limited to the configuration in which the power generation output of the engine-driven generator 18 is controlled to 0 when the average power consumption Pave falls below the minimum power generation output PgMin. For example, as shown in FIG. 7, in step 108 or 124, the average power consumption Pa
When it is detected that ve falls below the minimum power generation output PgMin, the minimum power generation output PgMin may be set as the control target Pg in the current control cycle (138). In that case,
Since a power generation surplus equivalent to PgMin-Pave occurs, the value of the management variable Pd is reduced by PgMin-Pave (13
6). In this case, the engine 22 is always in the WOT operation except when the vehicle is stopped. Further, a value higher than the minimum power generation output PgMin, for example, a control target Pg in the immediately preceding control cycle may be set as the control target Pg in the current control cycle.

Fifth embodiment. Further, as shown in FIG. 8, the engine may be idling (or stopped) immediately when the motor power consumption Pm substantially falls below the minimum power generation output PgMin. In this figure, first, the motor power consumption Pm obtained in step 104 is compared with the idling transition value Px set to a value smaller than the minimum power generation output PgMin by a minute amount of about 1 kW (140). As a result of this comparison, when Pm <Px is established, the operation after step 142 is executed, and when not established, the operation after step 102 is executed.

In step 142, the generator controller 34 controls the power generation output to zero by idling the engine 22 and controlling the field current If to a predetermined value such as zero. After this, the generator controller 34
Repeatedly samples the motor power consumption until Pm> Py is satisfied (144) (146). This Py
Is a threshold value for returning to the WOT operation, and is set to be larger than the minimum power generation output PgMin by, for example, about 1 kW. When Pm> Py holds, the generator controller 34
Executes the control of the power generation output so that the power generation output of the engine-driven generator 18 becomes a value equal to or larger than the minimum power generation output PgMin (148). Thereafter, the operation of the generator controller 34 returns to step 140 or step 100.

Such an operation, that is, the motor power consumption Pm is compared with the minimum power generation output PgMin (or values close to Pg and Py), and the engine 22 is immediately idling when a decrease in the motor output is detected. By (or stopping), the period in which the engine 22 is idling (or stopped) and the period in which the motor output is decreasing can be matched. This leads to preventing the noise of the engine 22 from being exposed and improving the drive feeling.

Further, the idling transition value Px and WOT
Since the hysteresis characteristic is given to the control by the return value Py, even if the motor power consumption Pm or its smooth value fluctuates near the minimum power generation output PgMin, the operating state of the engine 22 changes from WOT to idling or On the other hand, it does not fluctuate frequently, which also improves fuel efficiency. Further, since the control target used in step 148 can be, for example, the minimum power generation output PgMin or the previous power generation target Pg, the power generation output rapidly increases immediately after the idling period of the engine 22 ends up, and as a result, the noise of the engine 22 increases. It is possible to prevent the situation where the driving feeling is deteriorated due to the manifestation of.

Sixth Embodiment. The present invention is not limited to the configuration in which the control target Pg is limited to the upper limit by the power generation target limit value PhMax as in the second embodiment. For example,
The power generation target limit value PhMin is newly used to limit the lower limit of the control target Pg, and the power generation target limit values PhMax and Pmax are set.
In hMin, the correction by the management variable Pd may be limited. Further, when the average power consumption Pave falls below the minimum power generation output PgMin, the engine 22 is not simply idled or the engine-driven generator 18 is operated at the minimum output power generation, but the imbalance of the charge / discharge balance is ignored as a result of idling. The engine-driven generator 18 may be caused to perform the minimum output power generation operation when it becomes impossible.

FIG. 9 shows a control procedure executed by the generator controller 34 in the sixth embodiment of the present invention. In this embodiment, in step 124, the average power consumption Pave is compared with the maximum power generation output PgMax and the minimum power generation output PgMin. As a result, PgMax
If <Pave is satisfied, steps 110 and 112 are executed as in the above-described embodiments.

Also, PgMin≤Pave≤PgMax
If is satisfied, first, whether the management variable Pd is positive or negative is determined (150). When it is determined that the value of the management variable Pd is 0, it can be considered that the charge / discharge balance of the battery 16 is balanced, and thus step 12
6 is executed. When the value of the management variable Pd is positive, it can be considered that the charge / discharge balance of the battery 16 is inclined toward the discharge side. Therefore, in principle, the average power consumption P
The value obtained by adding the value of the management variable Pd to ave is the control target P
g (118C), the power output is controlled (120
C), and the management variable Pd is also reset to 0 (1
22C). As a result, it is possible to eliminate or reduce the inclination of the charge / discharge balance toward the discharge side that has occurred in the conventional control cycle.
On the other hand, when the value of the management variable Pd is negative, it can be considered that the charge / discharge balance of the battery 16 is inclined toward the charging side. Therefore, as a general rule, the average power consumption Pave is set to the management variable Pd. The value obtained by adding the values is set as the control target Pg (118D), the power generation output is controlled (120D), and the management variable Pd is reset to 0 (122D).
As a result, it is possible to eliminate or reduce the inclination of the charge / discharge balance toward the charging side that has occurred in the previous control cycle.

Further, if the value obtained by adding the value of the management variable Pd to the average power consumption Pave is out of the range in which the engine 22 can be WOT-operated, the WOT operation is continued in this embodiment, so that the step 118C or 118D
After execution, Pref is compared with the minimum power generation output PgMin and the maximum power generation output PgMax (124A, 124).
B). Pref> P when step 118C is executed
When gMax is satisfied, steps 110A and 112A having the same contents as steps 110 and 112 are executed without executing steps 122C and 120C.
If Pref ≦ is satisfied when Step 118D is executed, Steps 122D and 120D are executed.
Is executed, steps 136A and 138A having the same contents as steps 136 and 138 are executed.

Further, when the value of the management variable Pd is not 0, step 152 or 154 is executed. In step 152, the average power consumption Pave is compared with the power generation target limit value PhMax, and as a result, Pave ≧ Ph
If Max is satisfied, the process proceeds to step 126 without proceeding to step 118C. As a result, when the average power consumption Pave is large, steps 118C and 120C are performed.
Can be prevented from being executed, and thus a sudden increase in power generation output can be prevented. On the contrary, in step 154, the average power consumption Pave is the power generation target limit value PhMin.
(PgMin <PhMin <PhMax),
As a result, if Pave ≦ PhMin is satisfied, the process proceeds to step 126 without proceeding to step 118D. Accordingly, it is possible to prevent steps 118D and 120D from being executed when the average power consumption Pave is small, and thus it is possible to prevent a sudden decrease in the power generation output. These lead to improved feeling.

In step 124, Pave <Pg
When Min is satisfied, as a general rule, steps 136 and 138 are executed as in the fourth embodiment shown in FIG. 7. In this way, when the average power consumption Pave is reduced, the engine-driven generator 18 is caused to generate minimum output power instead of idling the engine 22,
The same effect as the fourth embodiment can be obtained. However, with this alone, when the minimum output power generation continues for a long time, the battery 1
There remains a problem that the charge and discharge balance of No. 6 gradually tilts toward the charge side. Therefore, in this embodiment, the engine stop threshold value PsFull having a negative value is compared with the value of the management variable Pd (156). Pd ≧ PsFull is satisfied when the value of the management variable Pd is a positive value (that is, when the charge / discharge balance is inclined toward the discharge side).
Alternatively, step 138 is executed because it is a negative value but its absolute value is not so large (that is, when the charge / discharge balance is inclined to the charging side but the degree thereof is not a problem). Conversely, Pd <P
Since sFull is satisfied when the value of the management variable Pd is a negative value and its absolute value is large (that is, when the charge / discharge balance is significantly inclined to the charge side), the further sFull is satisfied. The engine 22 is stopped (158) to prevent the occurrence of balance.

Even after the engine 22 is stopped, the generator controller 34 clears the timer to 0 and then starts counting (160), and continuously samples the motor power consumption Pm (162). When the timer measures T seconds (164), the generator controller 34 obtains the average power consumption Pave for T seconds (166). At this point of time, the engine 22 is stopped and therefore the power generation output is 0. Therefore, the calculated average power consumption Pave is the power generation shortage that has occurred during T seconds while the engine 22 is stopped, that is, the discharge from the battery 16. It represents the amount of electricity. Therefore, the generator controller 34 reflects this discharge in the value of the management variable Pd by executing step 114. If the value of the management variable Pd is 0 or more at that time (168), it can be considered that the inclination of the charging / discharging balance toward the charging side has been eliminated, and therefore the generator controller 34 starts the engine 22 (170). . While the value of the management variable Pd is less than 0, the generator controller 34 performs step 1
Returning to 60, the aforementioned operation is executed.

Therefore, even if the motor power consumption Pm is kept low for a long time, such an operation can prevent the charging / discharging balance from being significantly inclined toward the charging side. Further, by stopping the engine 22, fuel consumption by the engine 22 can be reduced.

[0059]

As described above, according to the present invention,
The control target of the power generation output set based on the smoothed value of the motor output in the immediately preceding control cycle is compared with the maximum power generation output that can be supplied from the generator. The discharge output equivalent value of is integrated into the control variable, and the control target set based on the smoothed value of the motor output falls below the maximum power generation output in the control cycle. Since the power consumption is compensated for, the charge and discharge balance of the battery can be satisfactorily and early balanced even when the generator and the battery are rated small for the required acceleration performance and the like. As a result, the life of the battery can be extended, the frequency of charging by the external power supply can be suppressed, the battery can be prevented from being over-discharged, and the battery voltage and the motor output can be prevented from decreasing and the generator and the battery can be prevented from becoming large. be able to.

According to the present invention, since the increase correction amount is limited so that the control target does not exceed the allowable output, the control cycle immediately before, for example, immediately after the transition from high load traveling to medium / low load traveling is performed. Even in the control cycle in which the motor output is reduced and the motor noise is reduced compared to the above, it is possible to prevent the noise from being actualized due to the increase in the power generation output, and reduce the discomfort in the drive feeling. Further, it is possible to prevent the increase of the battery voltage due to the increase of the power generation output and the occurrence of loss due to the decrease of the battery charging efficiency. Further, in the case of adopting a system configuration in which power generation is stopped when the battery voltage rises, from the viewpoint of overcharging the battery, preventing gas generation in the battery, and the like, it is possible to prevent such activation of the protection function.

According to the present invention, the increase correction amount is further limited so that the increase amount of the control target does not exceed the allowable increase amount. Therefore, for example, when shifting from high load running to medium / low load running. Even when the motor output is greatly reduced as compared to the immediately preceding control cycle, the power generation target and, by extension, the power generation output does not suddenly increase, so that no discomfort occurs.

According to the present invention, when it is determined that the control target set based on the smoothed value of the motor output is lower than the minimum power generation output capable of operating the engine with high efficiency, the control target is set to 0 or the minimum power generation. The value of the control variable was reduced by reducing the value of the control variable when the difference between the control target before the compulsory setting and the control target after the compulsory setting was added to the control variable, and the value was exceeded. Since the control target is corrected by the amount, the engine can be controlled to either the high-efficiency operating state or the stopped (or idling) state, resulting in suitable prevention of fuel consumption deterioration and reduction of motor output. Accordingly, the charge / discharge balance of the battery that is temporarily inclined to the discharge side or the charge side can be balanced at an early stage.

Further, according to the present invention, when it is recognized that the motor output is substantially lower than the minimum power generation output, the engine is idled or stopped, and thereafter the time when the motor output substantially exceeds the minimum power generation output. Since the power generation output is controlled with a value equal to or greater than the minimum power generation output as the control target, it is possible to match the period when the engine is idling or with the period when the motor output is decreasing, and the engine noise becomes visible. It is possible to prevent deterioration of drive feeling. Further, by appropriately setting the control target value to be adopted after the end of the engine idling or stop control, the imbalance of the battery charge / discharge balance during the period when the engine is idling or stopped can be compensated, and the life of the battery can be extended. It is possible.

[Brief description of drawings]

FIG. 1 is a block diagram showing a system configuration suitable for implementing the present invention.

FIG. 2 is a diagram showing control characteristics of an engine-driven generator.

FIG. 3 is a flowchart showing a control procedure of the generator controller in the first embodiment of the present invention.

FIG. 4 is a timing chart showing a control procedure of the generator controller in this embodiment.

FIG. 5 is a flowchart showing a control procedure of a generator controller according to a second embodiment of the present invention.

FIG. 6 is a flowchart showing a control procedure of a generator controller according to a third embodiment of the present invention.

FIG. 7 is a flowchart showing a control procedure of a generator controller according to a fourth embodiment of the present invention.

FIG. 8 is a flowchart showing a control procedure of a generator controller according to a fifth embodiment of the present invention.

FIG. 9 is a flowchart showing a control procedure of a generator controller according to a sixth embodiment of the present invention.

[Explanation of symbols]

10 motor, 16 battery, 18 engine drive generator, 22 engine, 24 generator, 30 controller, 32 motor controller, 34 generator controller, If field current, PgMax maximum power generation output,
PgMin Minimum power generation output, Pm Motor power consumption, P
ave average power consumption, Pd management variable, Pg control target, PhMax, PhMin power generation target limit value, Pt
r Power generation target increase limit value.

Claims (5)

[Claims] 1. A hybrid electric vehicle that is capable of driving a vehicle running motor using the discharge output of a chargeable / dischargeable battery and the power generation output of a generator driven by an engine and also capable of charging the battery with the power generation output. In the generator control device that controls the power generation output and manages the battery charge state, a means for setting a control target of the power generation output in the current control cycle based on the smoothed value of the index value of the motor output in the immediately previous control cycle. , A means to determine whether the set control target exceeds or falls below the maximum power generation output that can be supplied from the generator, and when it is determined to exceed it, the control target is reduced and corrected so that it falls below the maximum power generation output. , A means for adding the value obtained by subtracting the control target after reduction correction from the control target before reduction correction to the variable for charge / discharge balance management, When the power generation output is determined, the amount equal to or less than the value obtained by subtracting the control target from the maximum power generation output is subtracted from the charge / discharge balance management variable and the reduced amount is added to the control target, and power is generated according to the control target. And a means for controlling the power generation output of the generator. 2. The generator control device according to claim 1, wherein when the control target is lower than the maximum power generation output, the control target does not exceed an allowable output having a value equal to or less than the maximum power generation output. A generator control device comprising means for limiting the amount of addition to a control target. 3. The generator control device according to claim 1, wherein when the control target is below the maximum power generation output, the control target is controlled so as not to increase by a predetermined allowable increase amount or more. A generator control device comprising means for limiting the amount of addition. 4. The generator control device according to claim 1, wherein the set control target is above or below a minimum power generation output capable of operating the engine with high efficiency, and when it is determined to be below. , Means for adding the value obtained by subtracting the control target after the forced setting from the control target before the forced setting to the variable for charge / discharge balance management, while forcibly setting the control target to 0 or a value greater than or equal to the minimum power generation output, When it is determined that the control target is subtracted from the maximum power generation output, the charge and discharge balance management variable is reduced by an amount equal to or less than the value, and the reduced amount is added to the control target. Generator control device. 5. The generator control device according to claim 1, wherein a means for detecting that the motor output is substantially below the minimum power output based on the index value, and a case where it is detected to be below, A means for idling or stopping the engine, a means for detecting that the motor output substantially exceeds the minimum power generation output based on the above index value, and a control target when the above is detected as the minimum power generation output. A generator control device comprising: means for forcibly setting to the above value.